Tungsten carbide is used in a wide variety of products such as cutting tools, wear parts and mining drill bits. Its toughness and hardness makes it excellent for these applications. In order to improve the hardness of tungsten carbide, the grain size of the cabide should be as small as possible. It is known that nanograin-sized tungsten carbide powders can be produced by a combination reductionicarburization process. This permits the tungsten carbide to be used in very demanding applications.
The current process to manufacture nanophase tungsten carbide, as well as tungsten carbide cobalt composites typically involves several processing steps. Initially, the tungsten composition is subjected to a reductive decomposition, followed by a gas-phase carburization. This results in the formation of many stable intermediates such as substoichiometric tungsten carbides, elemental tungsten and tungsten dioxide. The stability of these intermediate products significantly increases the carburization cycle time.